KR20010021613A - Gps guided munition - Google Patents

Abstract

The present invention relates to a tail fin assembly having a housing having a shape attached to a munition, at least one flight control surface, an actuator affecting the movement of the flight control surface to guide the munition, and an induction system for controlling the actuator mechanism. will be. The induction system has a satellite positioning system (GPS) receiver to influence the control of the actuator mechanism.

Description

GPS guided munitions {GPS GUIDED MUNITION}

This patent application, filed February 27, 1997, is a US patent entitled ON-THE-FLY ACCURACY ENHANCEMENT FOR CIVIL GPS RECEIVERS, the disclosure of which is incorporated herein by reference. Part of the ongoing application of 08 / 806,685.

The use of airborne munitions in war is well known. Such munitions generally include housings on tubes generally filled with substantially explosives, shock fuses to detonate explosives and noses with detonators, and pins to stabilize the operation of munitions during descent, thereby impacting the targets and the noses by Explosion is working properly. The use of these airborne munitions could destroy enemy targets, making great advances in warfare technology, and reducing undesired loss of life and / or destruction of military equipment.

However, as those skilled in the art will appreciate, conventional munitions should generally be dropped with extremely high accuracy or in extremely large quantities to effectively destroy the desired target. Therefore, it is often necessary to drop these munitions undesirably at low altitudes or with undesirably large numbers of sorties. Dropping conventional munitions below the desired altitude exposes planes and crew to deadly AA guns and surface to air missiles. The accuracy of these AA guns and surface-to-air missiles is greatly enhanced by the reduction in target range (aircraft altitude) due to low-flying. For this reason, low altitude bombing is so dangerous that it is rarely carried out. Of course, many undesirable sorties are expensive and time-consuming, and frequently expose planes and crews to air defense weapons such as anti-air guns and surface-to-air missiles.

Therefore, a number of sorties must be made to compensate for the lack of accuracy that naturally follows when these conventional munitions are dropped at a sufficient altitude to greatly mitigate the effectiveness of anti-air guns and / or ground-fired missiles. In this way, the mass shipment of such conventional munitions to the target compensates for the decrease in accuracy due to high altitude bombing, thus increasing the probability of destroying the target.

In an attempt to overcome the lack of reliable destruction of conventional munitions' ground targets, smart munitions have been developed, particularly for dropping at high altitudes. These smart munitions use guidance and flight control systems to maneuver munitions to desired targets. The guidance system gives a control signal to the control surface based on the current position of the munition and the position of the target, so that the control surface maneuvers the munition toward the target. Such induction systems operate according to known principles and generally employ techniques such as laser induction, infrared induction and / or radar. These guided munitions can reliably destroy enemy targets by flying high enough to greatly reduce the effectiveness of anti-aircraft guns and / or ground-launched missiles and greatly reduce the number of sorties.

It is well known to use a satellite positioning system (GPS) to guide a variety of munitions to their intended targets. Multiple GPS satellites are being implemented or are in the planning phase to provide accurate navigation information and positioning to the appropriate receiver or station at any location on the earth's surface. These GPS systems include the NAVSTAR Navigational Satellite Timing and Ranging Global Positioning System (NAVSTAR), a GLONASS system planned by the Soviet Union, and two European systems, known as NAVSAT and GRANAS, currently under development. For ease of explanation, the following discussion and disclosure focuses on features, particularly when used with NAVSTAR GPS, but the invention applies equally to other satellite positioning systems.

The NAVSTAR GPS, operated by the US government, has four orbital GPS satellites in each of six separate circular orbits, making a total of 24 GPS satellites, 21 of which are active and three of which are redundant. The satellite orbits lie on planes that are inclined to each other, not to poles or equators, and each satellite orbits the earth approximately once every 12 hours, making exactly two revolutions during one rotation of the earth. This arrangement allows at least four satellites to enter the same field of vision 24 hours a day throughout the world. The position of each satellite at a given time is known precisely and the navigation signal is continuously transmitted to Earth to provide position information indicating the position of the satellite in space with respect to time (GPS time). This location information is known as ephemeris data. In addition to the ephemeris data, the navigation signal transmitted by each satellite includes an indication of the precise time at which the signal is transmitted. Thus, the distance or range between the navigation signal receiver and the transmitting satellite uses this time indication to 1) indicate the time the signal is received at the receiver, 2) calculate the amount of propagation delay, i.e. the difference between the transmission time and the reception time, , 3) can be determined by multiplying the propagation rate of the signal by the delay amount. As a result of this determination, a pseudorange from the transmitting satellite to the receiver is calculated. This distance is referred to as the pseudorange because the receiver's clock is not precisely synchronized to the GPS time, and inaccuracies are caused by factors such as delay induced in the navigation signal propagation time by delivery through the atmosphere. This inaccuracy results in clock bias (error) and standby bias (error), respectively, which may be several milliseconds. In any case, using the two information in the navigation signal, ephemeris data and pseudoranges transmitted from at least four satellites, the position and time of the receiver relative to the center of the earth can be determined using passive triangulation techniques. have.

A more detailed discussion of NAVSTAR GPS can be found in B.W. Parkinson and S.W. Article by Gilbert NAVISTAR: Global Postioning Sysetm-Ten Years Later, (IEEE Newsletter, Vol 71, No 10, October 1983) and GPS: A guide to the Next Utility (Trimble Navigation, Sunnyvale, California, USA) 1989, pages 1-47, both of which are incorporated herein by reference.

NAVSTAR GPS considers two types of code modulation for carrier propagation pseudorandom signals. In a Coarse / Acquisition code, which is a first scheme, a carrier is modulated by a C / A signal and referred to as a C / A code, and also referred to as a Standard Positioning Service (SPS). The second way of modulation is generally referred to as precision or protection (P) code, and also referred to as Precise Positioning Service (PPS). The cryptographic version of the P-code, or Y-code, is intended to be used only by terrestrial receivers specifically approved by the US government to keep the Y-code sequence secret and not publicly available. This increases the number of NAVSTAR GPS users who rely solely on data provided through C / A code modulation, which unfortunately results in reducing the accuracy of the positioning system. The U.S. government also alters the clock parameters to induce errors in the C / A code GPS signal transmitted from the GPS satellites, i.e. deliberately disturbing the phase and frequency of the satellite clocks, thereby slightly altering the clock parameters for one or more satellites. Or by making a large modification, which selectively compromises GPS, this strategy is known as selective availability, or simply SA. SA can operate for a number of reasons, and the Department of Defense can operate for national security. Even if SA is operational, the US government can still use NAVSTAR GPS because it has access to compensation measures that eliminate the SA effect. However, uncompensated C / A code data is greatly degraded, that is, degraded. In view of the above, a C / A code modulation receiver is referred to as a civilian or civilian receiver or equipment, and a Y-code receiver is referred to as a military receiver or equipment. For the sake of generalization, a civil receiver refers to a GPS receiver or equipment of variable or deteriorated accuracy, and a military receiver refers to a GPS receiver or equipment of accurate accuracy or a GPS receiver or equipment of good accuracy.

In many applications of GPS, in order to reduce cost and complexity, even if a user has access to a secret key capable of precision positioning service (PPS) accuracy, it may be desirable to use a civil GPS receiver, for example, in a mobile or consumer vehicle. desirable. This is especially true for weapons that fire from consumable vehicles or some form of launch vehicle. If the user is authorized for PPS, the launch vehicle may have a military GPS receiver that is more accurate than civil equipment installed in a consumable vehicle.

Differential GPS (DGPS) correction processing is available for high accuracy civil GPS applications, which requires fixed inspection antenna coordinates and requires near real-time correction from the base station. Most civil GPS receivers have inherent accuracy limitations, primarily due to the deliberate deterioration induced in the signal by the US Department of Defense, which can be removed by DGPS processing. The accuracy of a civil GPS receiver is generally referred to as standard positioning service or SPS as described above and is better than 100 meters without differential correction. Some of the accuracy limitations are due to the use of only one frequency, which hinders the measurement of errors due to ion layer delay, and the use of coarse / acquisition (C / A) codes instead of more accurate precision P (Y) codes. The first factor contributing to the limitation is the SA which intentionally disturbs the phase and frequency of the satellite field of view. Military equipment eliminates SA errors by algorithms using data available only to authorized users through the use of cryptographic keys. In addition, the user of the receiver can track a second frequency that allows measurement and compensation of the ion layer delay.

However, these guided munitions are inherently vulnerable to being extremely accurate and therefore extremely expensive, even if they are extremely effective at destroying ground targets even when they are falling from high altitudes. Guided munitions themselves are much more expensive than conventional, i.e., non-induced, munitions, as well as airplanes carrying munitions have to undergo extensive and very expensive modifications to carry them. In general, avionics and control devices are additionally consumed in the cockpit, wired from the cockpit to a pile of bombs, or pylons, and weapons-specific electronic and mechanical interfaces are to be installed in guided munitions. Because these are expensive, these guided munitions are usually secured only for targets of very high strategic value.

In view of the above, it is desirable to provide a munitions article, that is, an airborne munitions article, which is much cheaper than a guided munition article while improving accuracy than the conventional munitions article.

The present invention relates generally to munitions such as bombs, and more particularly to GPS guided munitions using low cost civil GPS receivers in munitions in order to provide a cost competitive weapon system. Differential GPS (DGPS) correction processing is used to improve the accuracy of GPS guided munitions. According to a preferred embodiment of the present invention, the aftermarket tail pin kit is installed to convert the existing non-guided munitions to GPS guided munitions simply and inexpensively. Automated bomb control eliminates the need for expensive airplane modifications.

1 shows that the position of the aircraft is continuously updated through the military GPS receiver and the position of the munitions is continuously updated by the aircraft's military GPS receiver until launch, and subsequently by the aircraft in the built-in civil GPS receiver. Drawing showing munitions falling on the target.

2 shows a single plane dropping a plurality of munitions on a single target, and a single plane dropping a single munitions on a plurality of targets.

Figure 3 shows a plane equipped with GPS guided munitions in the case where the munition includes a tail pin kit according to the present invention, and also shows an automatic bomb control device strapped to the crew legs.

Figure 4 is a side view showing a GPS guided munitions, that is, a plane loaded with a bomb according to a preferred embodiment of the present invention.

Figure 5 is a schematic diagram showing the verification and testing of GPS guided munitions, mission data loading and flight according to the present invention.

6 is a block diagram showing the interaction of a bomb control device disposed in an airplane with a tailfin kit of GPS guided munitions.

Fig. 7 is a block diagram showing compatibility with an airplane equipped with a bus of GPS guided munitions according to the present invention.

Fig. 8 is a block diagram showing a navigation system for GPS guided munitions according to the present invention.

Fig. 9 is a flowchart showing steps related to most missions using GPS guided munitions according to the present invention.

Fig. 10 is a flowchart showing preparation for launching a GPS guided munition of the present invention.

Figure 11 is a top view showing the control and display of the bomb control device of the present invention.

12 is a block diagram of a bomb control device of the present invention.

Figure 13 is a flow chart showing the initialization of the bomb control device of the present invention.

Figure 14 is a partial perspective view showing the induction and flight control element of the tail pin kit (TK10) of the present invention.

Figure 15 is a baseline block diagram of the tailpin kit of the present invention.

Figure 16 is a flow chart showing the operation of the tail pin kit according to the present invention.

Fig. 17 is a block diagram showing a Kalman filter of the navigation device of the tail pin kit according to the present invention.

The present invention addresses and improves on the drawbacks described above in connection with the prior art. More specifically, the present invention includes a tail pin assembly for munitions such as bombs. Hereinafter, the term munition is defined to include bombs, missiles, shells, and the like. The tailpin assembly includes a housing shaped to be mounted to the munition, at least one flight control surface, an actuation mechanism that affects movement of the flight control surface to guide the munition, and an induction system to control the actuation mechanism. The guidance system includes a satellite positioning system (GPS) that affects the control of the actuation mechanism.

According to a preferred embodiment of the invention, the guidance system comprises a civil GPS receiver. The tailpin assembly includes a radio receiver for receiving control signals from the plane. Preferably the flight control surface comprises at least three fins, preferably four fins.

The present invention also relates to a weapon system included in an airplane. The munition includes a bomb control device which is mounted on an airplane so that it can be dropped and communicates with the munition as described above, and provides the munition with guidance information that improves the accuracy of the GPS system of the munition.

The explosive control device includes a GPS receiver with higher accuracy than a military GPS receiver. According to a preferred embodiment of the present invention, the bomb control device includes a military GPS receiver and the munition includes a civil GPS receiver. According to another embodiment of the present invention, the bomb control device has a military and civil GPS receiver and the munition includes only a civil GPS receiver.

If the bomb control device includes only military GPS receivers, the GPS guided munitions from the military GPS receivers are provided with more accurate location information at the time of release, improving the accuracy of the GPS munitions, thereby improving the accuracy of the guidance system.

If the bomb control device includes both military and civil GPS receivers, an offset or error signal is generated that reflects the difference between the positions indicated by the military and civil GPS receivers, and these offsets are transmitted to the GPS guided munitions to improve their accuracy. .

On the other hand, if the bomb control device includes only a military GPS receiver, such an offset may be selectively generated for the civilian GPS receiver of the GPS guided munition, and these offsets are provided to the GPS guided munition by the bomb control device.

The GPS guided munitions of the present invention may be implemented as a tailpin kit used as an aftermarket addition to existing munitions such as the MK82 500 pound bomb. Meanwhile, the GPS-guided munitions according to the present invention include bombs or other munitions having a GPS guidance system, and the flight control system of the present invention is integrally formed therewith.

As those skilled in the art will appreciate, when the GPS guided munition of the present invention is implemented as a tailpin kit, the original tailpin of the munition, such as the MK82 500 pounds of tailpin, must be removed and replaced with the tailpin of the present invention.

Bomb control devices include radio transmitters, and munitions, including radio receivers, allow the bomb control device to transmit control and guidance information to GPS guided munitions without the need for modifications to the plane, ie expensive wiring. The GPS guided munitions may include a radio transmitter for transmitting information such as a wait signal from the GPS guided munitions to the bomb control device. In this case the bomb control device as well comprises a receiver for receiving this information.

Also in accordance with a preferred embodiment of the present invention, the bomb control device comprises a fully automatic device that does not require power or any other connection to the aircraft, which allows the use of the GPS guided munitions of the invention without modification of the aircraft. Therefore, the GPS-guided munitions of the present invention merely load the munitions into a mechanically compatible pylon or bomb release mechanism, install a bomb control device to the pilot or other crew, preferably strap the crew's legs to various existing planes. It is available. Thus no electrical or mechanical modification of the plane is required.

According to a preferred embodiment of the present invention, the GPS guided munition further includes an inertial guidance system and includes at least one rolling rate gyroscope for detecting a change in the rolling attitude of the GPS guided munition to enable proper flight control. do.

According to another embodiment of the GPS guided munition of the present invention, the GPS guided munition includes two antennas for the civil GPS receiver of the GPS guided munition. The antenna is arranged on each of two different pins of the GPS guided munitions, and the switching circuits alternate the connection of the GPS receiver to each of the two antennas in series. Thus, two antennas can be used to determine the rolling posture of the munition, eliminating the need for a rolling rate gyroscope.

The above features together with other advantages of the present invention will become apparent from the following description and drawings. It is to be understood that the changes and specific structures shown and described below are made within the scope of the claims without departing from the spirit of the invention.

The detailed description set forth below in connection with the appended drawings is intended as a description of preferred embodiments of the present invention of the present invention and is not intended as the only form in which the present invention may be realized or used. Functions and a series of steps for implementing and operating the present invention in connection with the described embodiments are described below. It is to be understood, however, that the same or equivalent functions may be achieved by other embodiments that are intended without departing from the spirit and scope of the invention.

According to a preferred embodiment of the present invention, a tail pin kit incorporating a civil GPS receiver can activate the munitions after release.

The accuracy of GPS guided munitions with civil GPS receivers is improved by providing location updates and / or error signals from military GPS receivers deployed in the aircraft. The military GPS receiver is preferably placed in a bomb control device which alleviates the need for retrofitting the plane by strapping to the crew's legs.

The GPS guided munitions of the present invention are shown in Figs. 1-17, showing a presently preferred embodiment. As can be seen with reference to Figure 1, a bomb control device (see BCU Figure 3) according to the present invention is arranged in the cockpit and the aircraft 10 carrying at least one GPS guided munition four different positions according to the bombing mission , A, B, C and D. The plane 10 at position A is shown to be in permissions with the appropriate military GPS code loaded into the bomb control device.

As will be appreciated by those skilled in the art, an encryption key must be provided for a military GPS receiver to function properly. The target coordinates and the type of bomb are also usually loaded into the BCU during permission. The target coordinate is preferably transmitted from the bomb control device to the bomb at this time. Target coordinates, on the other hand, can usually be loaded directly into the munitions via a personal computer.

The plane 10 at position B is in GPS acquisition to receive military precision GPS data to precisely define its position. This usually occurs at time-on-target (TOT) of 25 minutes or more. At this time, the military GPS receiver in airplane 10 and the civil GPS receiver in GPS-guided munitions 12 receive a position update signal from GPS satellites 14 (only one GPS satellite is shown in FIG. 1 for clarity).

The plane 10 at position C is in pre-launch mode, which generally occurs about 2-3 minutes before the munition launch. At this time, the bomb control device calculates a continuously calculated release point (CCRP), a continuously computed impact point (CCIP), an airplane position and a heading que. Target coordinates are updated if necessary.

During pre-launch, the pilot needs to maintain horizontal flight, ie rolling below 5 degrees, while flying along the CCRP / line.

The rolling posture of the plane 10 during the dropout greatly affects the rolling posture of the GPS guided munitions 12 to be dropped, and the rolling posture of the dropped GPS guided munitions 12 greatly affects its accuracy. It is desirable to minimize it.

Depending on the rolling attitude of the GPS guided munitions 12, the accuracy of the GPS guided munitions 12 is affected by rolling since a separate flight control surface must be used to guide the GPS guided munitions 12 to the target. That is, the pins generally used to influence the right turn of the GPS guided munitions 12 when the GPS guided munitions 12 are in the first rolling position and the pins used when the GPS guided munitions 12 are in the second rolling position. This is different. The rolling attitude of the GPS guided munitions 12 is preferably monitored by an immature inertial guidance system comprising a rolling rate gyroscope, but using such an inertial guidance system as known to those skilled in the art additionally introduces undesirable errors. Induce. Therefore, to minimize this additional error, it is desirable to maintain the plane 10 in a generally horizontal position at launch. By doing so, the guidance system of GPS guided munitions 12 reduces the dependence of the rolling rate gyroscope for accurate guidance.

One or more GPS guided munitions 12 of the launch basket 18 are dropped from the plane 10. Because of the additional accuracy given by the GPS guided munitions 12, the GPS guided munitions 12 can be dropped at higher altitudes while maintaining the desired accuracy. The high altitude drop of these GPS guided munitions 12 greatly improves mission viability by providing greatly improved safety for the crew and the plane 10.

According to a preferred embodiment of the present invention, the accuracy of the munitions can be greatly improved without greatly increasing the cost. This is accomplished by using a civil GPS receiver (74 in FIG. 6) and a GPS guided munition 12. As will be appreciated by those skilled in the art, civil GPS receivers are significantly cheaper than military GPS receivers. Therefore, even if the military GPS receiver improves the accuracy of the GPS guided munitions, the present invention that the accuracy of the civil GPS receiver is greatly improved by maintaining communication with the military GPS receiver of the bomb control device 24, as discussed in detail below. Sufficient accuracy is obtained through the use of civilian GPS receivers by the methodology of.

Thus, the use of such GPS guided munitions 12 provides a good compromise between inaccurate non-induced gravity munitions, ie expensive guided bombs such as bombs and laser-guided smart bombs. As will be appreciated by those skilled in the art, the use of non-guided bombs generally requires the use of a large number of bombs to ensure destruction of the target, so it is necessary to increase the number of sorties. The use of non-guided bombs requires more dangerous low altitude drops to ensure target destruction.

The use of guided munitions, such as smart bombs, is extremely expensive and usually secured only for the most strategic targets.

The present invention provides a desirable compromise in cost and effectiveness. According to the present invention, the accuracy of the munitions is improved by the use of a bomb control device that does not require a low-cost retrofit of the munitions and the remodeling of the plane, thereby greatly reducing the number of sorties required to effectively destroy a desired target. .

According to a preferred embodiment of the present invention, a continuous operational impact point (CCIP) is given during the pre-launch phase. If the continuous operational impact point matches the target, then the desired GPS guided munitions are dropped. In this way, the trajectory trajectory of the GPS guided munitions 12 is such that the correction necessary for the GPS guidance system of the munitions 12 is minimized in order to ensure accurate impact on the target.

According to a preferred embodiment of the present invention, the GPS guided munitions 12 are dropped manually, i.e. through the operation of the pickle switch, thereby reducing the need for expensive modifications to the plane. However, as will be appreciated by those skilled in the art, it is desirable that the GPS guided munitions 12 be automatically dropped by providing electrical communication between the airplane's electronic and mechanical bomb release mechanism and the bomb control device 24.

This high altitude target time (TOT) is typically between 0.5 and 1.0 minutes. According to a preferred embodiment of the present invention, the bomb control device provides a drop countdown. As described above, the munitions may be manually dropped by the crew or automatically dropped by the bomb control device when the continuous operational impact point (CCIP) coincides with the target.

Once dropped, the GPS guided system of the GPS guided munitions 12 guides the munitions 12 toward the target 20. Therefore, unlike the case of the unguided munitions, the accuracy or timing of the release, the weather system, and the like rarely cause the GPS-guided munitions 12 to land from the target.

At this time, the plane 10 may receive an in-flight target update signal from a ground station transmitter (not shown) or from another plane 16. The in-flight target update signal may be transmitted to a crew member who transmits the target update to the GPS guided munition through the bomb control device, or may be transmitted to the GPS guided munition directly from the ground station transmitter or the airplane 16. As will be appreciated by those skilled in the art, various encryption and authorization methodologies may be used to verify the authority of the transmitter to change the target coordinates of the GPS guided munitions. Of course, two or more of the GPS guided munitions of the present invention may be carried in a single plane. In this case, a single bomb control device is preferably used to provide an interface for each of the GPS guided munitions. However, it is preferable that two or more different bomb control devices may be used.

With reference to FIG. 2, the dropping of a plurality of GPS guided munitions 12 by a single plane 10 for a single target 20 and a single plane 10 for a plurality of targets 20a-20c. The dropping of the some GPS guided munitions article 12 by this is shown. By using the GPS guided munitions according to the present invention, the single target 20 can be bombarded accurately by the plurality of GPS guided munitions 12 dropped from the single plane 10. Since the GPS guidance system of the GPS guided munition 12 corrects the error of the trajectory trajectory of the munition 12 induced by the dropping at different times corresponding to different continuous operational impact points (CCIPs), the accuracy of the GPS munition is improved. Is improved.

The GPS guided munitions in accordance with the present invention also enable the precise bombing of multiple targets during a single pass or munition flight. As will be appreciated by those skilled in the art, when there are a plurality of dense targets, the dense targets will be bombarded, and a plurality of passes will generally be required to provide the time required for the individual and accurate delivery of the munitions. However, when the GPS guided munitions according to the present invention are used, the GPS guided system compensates for these errors, so that the proportion of the accuracy of the dropped munitions is greatly reduced. Therefore, a plurality of such GPS guided munitions 12 may be dropped so that separate GPS guided munitions 12 are individually guided to their respective targets 20a to 20c. Accordingly, by reducing the number of bombing flights required to destroy a plurality of dense targets, the survival of the crew and the plane can be greatly improved.

Referring now to FIG. 3, the GPS guided munitions preferably comprise a bomb with a tailpin kit 22 installed. According to a preferred embodiment of the present invention, the tailpin kit is specifically designed to be mounted on a MK82 / EU2 500 pound bomb. As will be appreciated by those skilled in the art, MK82 / EU2 is a standard munition and is commercially available throughout most of the world. The tailpin kit 22 of the present invention thus provides a low cost, easy to use means for converting a standard 500 pound bomb into a relatively accurate weapon.

The BCU 24 preferably comprises a portable automatic device attached to a crew, preferably one leg, of a pilot 26 or the like via a strap 28. The bomb control device 24 is thus placed in a position that is easy to read and use of the display 30.

The bomb control device 24 includes an antenna 32 for accurately positioning the GPS guided munitions 12 via an embedded military GPS receiver. The bomb control device 24 also includes a communication link 34 with a GPS guided munition, including a civil GPS receiver, to allow its control and release to improve the performance of the guidance system.

The keypad 38 allows input of target coordinates, control codes, and the like. The bomb control device 24 may further include KYK-13 inputs 36 for inputting encryption keys required for use of military GPS receivers. Munitions I.D. The switch 40 preferably includes a selection switch that selects which of the plurality of munitions mounted on the plane 10 will be communicated at a specific time. Thus, the pilot 26 is merely a munitions I.D. The switch 40 is attached to the desired GPS guided munitions 12 and inputs target coordinates, for example.

While the GPS guided munitions 12 are on the ground, the personal computer 42 is preferably used to test the tail pin kit 22. The personal computer may also be used to upload target coordinates to the guidance system of the tailpin kit 22.

With reference to FIG. 4, the airplane 10 is part of or is isolated from the bomb control device 24 so as to be mechanically attached to a portion of the plane 10 and connected to the bomb control device 24 via conductors. Has The bomb control device radio frequency link antenna 46 may likewise be part of the bomb control device 24 or attached to the airplane 10 and then connected to the bomb control device 24 via a conductor.

The GPS guided munitions 12 likewise comprise a GPS antenna 48 and a bomb control device RF link antenna 50. The GPS antenna 44 of the bomb control device allows military and civilian receivers to operate. The GPS receiver and GPS antenna 48 allow civilian GPS receivers to operate. The bomb control device radio frequency link antenna 46 of the airplane 10 and the bomb control device RF link antenna 50 of the GPS guided munitions 12 communicate with the bomb control device 24 and the GPS guided munitions 12. To be able.

According to a preferred embodiment of the present invention, the bomb control device includes both a military GPS receiver and a civil GPS receiver, each of which allows a difference or an error of the military and civil GPS receivers to be easily calculated and transmitted to the GPS guided munitions 12. Share a common GPS antenna. In the comparative example of the present invention, only the military GPS receiver is embedded in the bomb control device 24 and the error between the military GPS receiver and the civil GPS receiver of the GPS guided munition 12 is calculated.

Referring to FIG. 5, the functions of verification and testing 52, mission data load 54 and flight 56 of the GPS guided munitions 12 are shown in detail. Verification and testing function 52 includes providing power from the power source 58 to the GPS guided munitions 12 and providing aiming and / or control signals from the personal computer 42 to the GPS guided munitions 12. do. The bomb control device 24 communicates with the personal computer 42 to provide an audio link from the bomb control device 24 to the personal computer 42 to verify correct operation of the audio output of the bomb control device 24. The audio link preferably provides an audible voice for instructing the crew 26 of various conditions, such as initializing the continuous operational impact point (CCIP) under test, weapons release and weapon impact simulation. Audio links are generally used to instruct pilots when they need to fly horizontally and stably before release to affect the calibration of the rolling rate gyro and to minimize rolling of GPS guided munitions during release.

During the mission data load 54, the personal computer 42, which has received the mission data in advance through a keyboard input, a floppy disk, a network, or the like, allows the mission control device 24 to load the mission data. The personal computer 42 may upload the mission data directly to the GPS guided munitions 12.

During the flight function 56, the GPS-guided munitions 12 provide GPS signals to civilian GPS receivers within the GPS-guided munitions 12 and also transmit radio signals, preferably UHF radio signals 60, from the bomb control device 24. GPS position data is received through the receiving GPS antenna 48.

Referring to FIG. 6, the bomb control device 24 generally includes a GPS antenna 44 mounted and disposed on the airplane 10 and in electrical communication with the military GPS receiver 62. Military GPS receiver 62 communicates with processor 64 which processes the output of military GPS receiver 62 for display 66. The bomb control device 24 may be used to communicate the aiming coordinates to the GPS guided munitions and to communicate the firing signal wait from the GPS guided munitions 12 to the bomb control device 24. You can also communicate with). Meanwhile, the bomb control device 24 has a built-in radio.

The GPS guided munitions 12 include a data interface and ground power port 70 that allow for testing and optionally uploading of target coordinates on the ground.

The munitions drop sensor 72 sends an instruction to the crew that the GPS guided munitions 12 have been dropped from the plane. The GPS antenna 48 receives GPS signals from the satellites 14 and sends GPS signals to the civil GPS receiver 74. The civil GPS receiver 74 sends an output to the sensor 78, i.e., the control electronics 76 in electrical communication with an inertial inductive sensor such as a rolling rate gyroscope. Control electronics 76 also electrically communicates with a control actuator 80 that affects the flight control surface, i.e., the motion of the pin, to cause the GPS guided munitions 12 to maneuver against the target.

The thermocell 82 and / or generator 84, ie the ram turbine, provides power to the GPS guided munitions 12.

Preferably, the munitions ID switch 86 located outside of the GPS guided munitions is such that the bomb control device 24 is used together with a plurality of other GPS guided munitions 12 on the same plane, and the bomb control devices of other planes are also used. The radio communication channel between the specific GPS guided munitions 12 and the bomb control device 10 is determined so as not to interfere with the other munitions. It is important to note that the design shown in Figure 6 does not require an airplane data bus. However, if an airplane data bus is available, it can be used on the other hand as in the embodiment of FIG. As shown in FIG. 7, the munition pylon 88 is supported downward from the aircraft wing 90. A DIGIBUS 1553 or 1760 interface is included in the munition pylon 88. In this case, the pylon adapter 92 includes a bus converter 94 and a radio 96 using airplane code 98 to uniquely identify the munitions on the plane. As before, the radio antenna 47 provides electrical communication between the plane 10 and the GPS guided munitions 12.

Referring to FIG. 8, military GPS receiver 62 of bomb control device 24 provides position and velocity output to bias calibration circuit 100 of bomb control device processor 102. According to a preferred embodiment of the present invention as described above, the bomb control device 24 also includes a civil GPS receiver 63 for providing a pseudo range to the bias correction circuit 100 of the bomb control device processor 102. The bias correction circuit 100 then sends a bias or error signal to the minimum square (LSQ) position fix circuit 104 of the tail pin kit 22 to improve the accuracy of GPS guidance of the GPS guided munitions 12. In order to improve the post-dropping accuracy of the GPS guided munitions 12 by improving the filtering capability, the position and velocity information from the military GPS receiver 62 can be gained from the military GPS receiver 62 by a canned-gain Kalman filter ( 106 may be provided. Navigation state estimator 108 provides position and velocity information to the guidance and control system.

Controlled accelerometer measurements may be provided from the inertial guidance system to aid in navigation state estimation and filtering.

With reference to FIG. 9, most sorties or bombardment missions in which the GPS guided munitions of the present invention are used are generally pre-takeoff 110, takeoff 112, aviation 114 to nearby point of release, and point approach 116. ), Preparation for release 118, weapon separation 120, rolling stabilization 122, putative navigation 124, and guidance to the target 126. Before takeoff 110 generally lasts for several hours. During takeoff 110, the pilot and the plane wait for the start of the mission in general. During this time the airplane engines may run.

Takeoff 112 typically lasts about 60 seconds. During takeoff 112, the plane moves and raises altitude, usually performing ground rolling. The power of GPS-guided munitions is usually available at takeoff, and civilian GPS receivers function at this time.

The flight 114 to the nearby point of release generally takes two hours. During this time the pilot maneuvers towards the point of release. Aircraft flight and mission planning is used to maneuver the plane to the point of release. Bomb control weapon checks and GPS day key resets are generally performed during this time. Current Ephemeris and Pseudorange modifications are broadcast on GPS-guided munitions. When the bomb control unit is not used, the bomb control unit may be turned off to conserve power. Bomb control devices are generally fully automatic and are therefore operated on battery power. Meanwhile, the bomb control device can be powered from an airplane. Of course, as described below, the bomb control device must be turned on during the point approach 116 to improve the accuracy with which the guidance system of the GPS guided munition 12 operates.

Drop point approach 116 generally lasts approximately 15 minutes. The bomb control device is switched on during the point approach 116. Mission 1 (or any other mission as appropriate) is selected to define the target coordinates. According to a preferred embodiment of the present invention, a plurality of different missions, each with its own target coordinates, may be pre-programmed in the bomb control device. Periodic ephemeris and pseudorange modifications are broadcast from the bomb control device 24 to the GPS guided munitions 12 to improve the accuracy of the guidance system.

Drop preparation 118 generally lasts approximately 3 minutes. During preparation for release 118, the bomb control device sends steering instructions to the pilot based on the plane's current position and speed and the target's position. The selected GPS guided munition initializes the navigation system. Initialization of a GPS guided munitions modification system includes a modification of the inertial navigation system. According to a preferred embodiment of the present invention, the initialization of the GPS guided munitions inertial guidance system includes a correction or zero adjustment of the rolling rate gyroscope. This can be achieved by flying horizontally as straight as possible to define the zero rolling output of the rolling rate gyroscope's rolling rate. During this period periodic ephemeris and pseudorange modifications are broadcast from the bomb control device 24 to the GPS guided munitions 12.

Inorganic separation 120 generally lasts about 2 seconds. One or more GPS guided munitions 12 are released or separated from the plane 10 during weapon separation 120.

Rolling stabilization 122 generally lasts about 3 seconds. Attempts are made to control the rolling rate of GPS guided munitions 12 to be as zero as possible during rolling stabilization 122. During this time the navigation system of GPS guided munitions 12 receives additional GPS location information via a civil GPS receiver.

Estimation navigation 124 generally lasts about 5 seconds after release. The GPS guided munitions 12 during the estimated navigation 124 are guided towards the target using the estimated navigation solution generated from the preloading condition of the GPS guided munitions 12.

Estimated navigation usually ends and GPS guidance takes over as soon as possible after launch. However, if the GPS signal is unavailable, i.e., jammed, the estimation navigation 124 continues until the impact.

Guidance to target 126 generally lasts about 17-35 seconds, depending on the speed and altitude of the plane at the time of release. Guidance to the target ends with the impact of the GPS guided munitions 12 on the target. Therefore, the GPS correction of the trajectory of the GPS guided munitions 12 is continued until the impact.

Referring to FIG. 10, preparation for launch includes actions performed by a crew member, pilot 26 of airplane 10, actions performed by bomb control device 24, and actions performed by GPS guided munitions 12. do. The crew or pilot 26 may use a dropping basket, i.e., a GPS guided munition drop point, by using a control command 134 generated by the bomb control device 24 based on the target's location as well as the plane's current position and speed. Steer the plane 10 to 130 (130). The pilot also needs to maintain a zero rolling rate and a constant Mach number and altitude, and the hold condition 136 is used to initialize 138 the navigation system of the GPS guided munition 12. When the hold condition is applied, the bomb control device broadcasts the location information to the navigation system of the GPS guided munition 12 (140). The audio signal generated by the bomb control device 24 indicates that information is being transmitted by the bomb control device 24 to the GPS guided munitions 12 and therefore needs to maintain the hold condition until the audio signal 142 stops. Let the pilot know.

During firing separation, the bomb control device 24 calculates the continuous calculation drop point (CCRP). The continuous calculation drop point is used to calculate 144 the time to the drop point. If the time to go is less than 90 seconds (146), the audio signal 142 is generated by the bomb control device 24 to inform the pilot that the overall condition 136 should be applied. Before directing the audio signal 142, i.e., if the time to the dropping point is 90 seconds or more, the BCU continues to calculate 144 the calculation time to the continuous operation dropping point (CCRP) and the dropping point.

During preparation for release, bomb control device 24 also performs GPS recitation 148 and calculates the pseudorange correction 150 broadcast to the navigation system of GPS guided munitions 12 to improve accuracy. The pseudorange correction 152 is sent to the GPS guided munitions 12 by the BCU 24.

Referring to FIG. 11, the bomb control device 24 includes a radio antenna 160 for broadcasting GPS data and control signals to the GPS guided munitions 12. The bomb control device 24 includes a display 30 for displaying the information about the GPS guided munitions 12 and the target as well as information on the flight of the airplane 10. The audio connector 162 allows the pilot to send an audio signal instructing the pilot to drive the plane 10 horizontally in a straight line to modify the inertial guidance system of the GPS guided munition 12. The GPS connector 164 enables connection to an external GPS antenna and is preferably mounted in the cockpit of an airplane. The selector switch 166 turns off the bomb control and puts it into standby mode to broadcast primary GPS, ie location information, or to operate in differential mode, ie send an error or differential GPS signal. Brightness and contrast control 168 preferably adjusts the brightness and contrast of the display 30.

Referring to Fig. 12, according to a preferred embodiment of the present invention, the bomb control device 24 includes a GPS antenna 32 for providing a signal to the power splitter 200. The power splitter sends output to Collins p-code GPS 202 and Motorola c-code GPS 204. Multiple transmitter 206 sends the R2-232 output to the built-in 4865L computer and sends the output to the compute of the embedded 486SL computer 208. The RS-232 output of the Collins p-code GPS 202 is sent to COM1 of the 4864 computer 208.

According to a preferred embodiment of the present invention, the bomb control device 24 also includes a test port that allows electrical communication with the GPS guided munitions 12 during system testing. The battery power supply 210 provides an internal source of power to automatically operate the bomb control device 24.

Also in accordance with a preferred embodiment of the present invention, the 486 SL computer 208 has a first PCMCIA interface 212 and a second PCMCIA interface 214. The first PCMCIA interface 212 may be a redundant PCMCIA interface or may be used for any particular use desired. The second PCMCIA interface 214 is preferably used to communicate with the solid state flash drive 216 having a capacity of about 20 megabytes.

The 486 SL computer 208 preferably includes preparation for a pointing device such as a trackball or mouse. On the other hand, instructions of the touch screen or other device may be used. The 486SL computer preferably provides output to the LCD graphic display 230.

According to a preferred embodiment of the present invention, the 486SL computer 208 further includes a PC printer port 218 for providing data to the RF data link and interface / scan logic interface 220. The RF data link and the interface / scan logic interface are in electrical communication with a radio receiver 222 sharing a radio receiver 222 and a radio antenna 226. Six discrete switches 228 send input to the RF data link and interlink / scan logic interface 220 and input a unique identification code to the bomb control unit so that the bomb control unit only communicates with the desired GPS guided munitions. To be able.

Referring to Fig. 13, during initialization of the bomb control device 24, the pilot first turns on the bomb control device 24 (300). This results in a first acquisition 302 by a civil GPS receiver and a first acquisition 304 by a military GPS receiver. The first acquisition 302 by the civil GPS receiver and the first acquisition 304 by the military GPS receiver generally take about 20 seconds. If the almanac is present (306), the first fixation (308) is sent. If no almanac is present (306), the almanac is collected (310). Almanac collection generally takes about 12.5 minutes. Ephemeris is collected 312 after the first fixation 308. This typically takes 30 seconds. GPS reception commences (148) and calculation of pseudorange correction (150) is achieved. GPS reception 148 in the calculation of the pseudorange correction occurs generally at a frequency of about 1 Hz. Next, the pseudorange correction is sent to the GPS guided munitions 12.

A check is made to verify that a key exists 314 for the military GPS receiver. If there is a key, a first lock 316 is sent by the military GPS receiver. Otherwise the key is collected 318 followed by a first lock 316. GPS reception 320 then continues at a rate of about 1 Hz. The target coordinates 322 are sent to enable operation 130 of the continuous operation drop point. The continuous operation drop point is used to calculate 144 the start time of operation. Processing of the continuous operation drop point and operation start time continues at a speed of about 20 Hz. Continuous calculation point longitude and latitude are also used to calculate 146 a direction indication that provides the pilot with a desired destination to the point of delivery and to calculate the operational start time (146). The GPS guided munitions 12 remain in standby mode 148 until the preparation for release begins.

Referring to FIG. 14, the tail pin kit for GPS guided munitions according to the present invention includes a housing 400 that can be mechanically attached to the rear end of a munition such as an MK82 / EU2 pound bomb.

The discussion and description of the MK82 / EU2 pound bombs below is for illustrative purposes only and is not intended to be limiting. Those skilled in the art can use the GPS guided munitions of the present invention with a variety of other existing munitions and it is desirable to use them in conventional designs as well.

The electronics module 402 is used to interface the amplitude sensor 404, the thermocouple 406, the ram air generator 408, the radio 410, the control actuator 412, the isolation sensor 414, and the GPS receiver 416. It includes a circuit. The amplitude sensor 404 incorporates an inertial navigation system that includes at least a rolling rate gyroscope. The thermocell 406 provides power for operating the electronics and control actuators immediately before and after dropping the GPS guided munitions 12. The ram air generator 408 may provide power or increase the output of the thermal cell 406 after the GPS guided munitions 12 are dropped. The radio 410 makes it possible to communicate with the bomb control device 24.

According to a preferred embodiment of the present invention, four separate control actuators 412 are provided for independent control surfaces or pins 418. Independent control of these pins allows the use of various flight control strategies, such as bank-to-turn and skid-to-turn. As will be appreciated by those skilled in the art, fewer than four control actuators 412 are preferably used.

A GPS antenna 48 located at the rear of the GPS guided munitions 12 allows for receiving location information from a GPS satellite via a civil GPS receiver 416.

Separation sensor 414 sends an indication that GPS guided munitions 12 have been dropped from airplane 10 to initiate automatic operation of GPS guided munitions 12.

Referring to Fig. 15, according to a comparative example of the present invention, the induction and control processor includes a 40 MHz 80106 processor 500, a radio frequency data link, a GPS interface EEPROM / RAM 504, an actuator interface / power amplifier 506. The 256K word memory 508 and the analog-to-digital converter 510 all use the CPU bus structure 502 mounted on the CPU bus 502. Transmitter 512 and receiver 514 are in electrical communication with RF data link and GPS interface EEPROM / RAM 504 and share a common GPS antenna 516. The actuator interface / power amplifier sends a position command to the actuator 518 and receives sufficient feedback therefrom. The analog to digital converter 510, when used, receives a signal from an accelerometer, a rolling attitude sensor, ie, a rolling rate gyroscope 520.

According to a preferred embodiment of the comparative example of the present invention, the induction and control processor 500 communicates with a data link 522 that is powered by the battery 524 and used for testing purposes only. Data link 522 has an antenna that can be used to simulate a bomb from bomb control device 24.

The GPS antenna 528 communicates with the Motorola c code GPS 530 which provides an RS232 output to the RF data link and GPS interface EEPROM / RAM 504. Thermocell 532 and / or ram air generator 534 cooperates with a DC-DC power supply 536 and a rectifier filter and battery squib 538 to supply power. According to a preferred embodiment of the present invention, the rectifier filter and battery stack 538, the DC-DC power supply 536, the Motorola c code GPS 530, the induction and control processor 500, the RF data link and the GPS interface EEPROM / RAM 504, actuator interface / power amplifier 506, 256K word memory 508, analog-to-digital converter 510, transmitter 512, and receiver 514 are all disposed on a single motherboard 540. However, those skilled in the art will note that other embodiments of these elements are likewise suitable.

Referring to Fig. 16, a block diagram illustrating the operation of the navigation and flight control system of the GPS guided munitions 12 is shown. Civilian GPS receiver 74 sends the pseudorange and rolling rate to navigation filter 550 providing position, speed, and wind vane to example 552.

Example 552 sends a signal at 100 Hz to the navigation buffer 554 at 1 Hz. Navigation buffer 544 sends a 100 Hz position velocity and rolling signal to inductor 556. Inductor 556 sends a control signal to controller 558. The controller 558 sends a pin control angle to the flight control system and receives the output of the navigation filter 550. The controller 558 also sends a measurement of the control applied to the navigation filter 550. Rolling rate gyro 560 sends output to both navigation filters 550 and controller 558. Accelerometer 562 may send output to dynamic pressure meter 564 where drag may be calculated and sent to navigation filter 550 if available. The dynamic pressure meter 564 sends an output to the controller 558.

Referring to FIG. 17, the control of FIG. 16 sends drag and applied control and three-dimensional coordinates to the navigation Kalman filter 600. GPS in-core receiver 602, which is a civil GPS receiver, sends velocity time data or pseudorange and rate range located in navigation Kalman filter 600 to navigation Kalman filter 600. Radio receiver 514 sends GPS in-core receiver 602 or pseudorange and velocity data to navigation Kalman filter 600. The navigation Kalman filter 600 sends position and velocity data to the short-term motion forecaster, which sends an output of 100 Hz at 1 Hz to the navigation buffer 554. The navigation buffer sends an output signal to the inductor as shown in FIG.

It should be understood that the GPS guided munitions described and described in the drawings represent only the presently preferred embodiments of the present invention. Various modifications and additions can be made without departing from the spirit and scope of the invention. For example, those skilled in the art will appreciate that various types of munitions, such as missiles, bombs, shells, etc., can utilize the GPS guidance of the present invention. In addition, the GPS guidance of the present invention need not be limited to air launch / drop munitions. Accordingly, other modifications and additions will be apparent to those skilled in the art and may be carried out to apply the present invention to its use in a variety of applications.

Claims (19)

In tail fin assembly for munitions, a) housing shaped to be attached to the munitions, b) at least one flight control surface, c) an actuator mechanism for directing the munition by moving the flight control surface; d) a guidance system for controlling said actuator mechanism, said guidance system having a satellite positioning system (GPS) for controlling said actuator mechanism; Tail pin assembly, characterized in that. The method of claim 1, And the guidance system comprises a civilian GPS receiver. The method of claim 1, And a radio receiver for receiving a control signal from the airplane. The method of claim 1, And the flight control surface comprises at least three pins. In a weapon system, a) airplane, b) munitions detachably attached to the plane; -The munitions are i) at least one flight control surface, ii) an actuator mechanism for directing the munitions by moving the flight control surface; iii) an induction system for controlling said actuator mechanism, Said guidance system having a satellite positioning system (GPS) for controlling said actuator mechanism; c) a control device that communicates with the munitions and provides the munitions with guidance information that improves the accuracy of the GPS system of the munitions; Weapon system comprising a. The method of claim 5, And the control device comprises a GPS receiver with greater accuracy than the GPS receiver of the munitions. The method of claim 5, The control device includes a military GPS receiver, and the munition includes a civil GPS receiver. The method of claim 5, And the control device includes a radio transmitter and the munition includes a radio receiver to allow communication of control signals and guidance data from the control device to the munition. The method of claim 5, And the control device is comprised of an autonomous device. The method of claim 5, And the control device is shaped to be attached to the leg of an airplane crew. In a method for transporting munitions, a) detachably attaching the munitions to the plane, b) communicating guidance information from the automatic control device to the munitions via radio, c) dropping munitions from the plane, d) directing the munitions toward the target using a positioning system Military supplies transport method comprising a. The method of claim 11, The munitions munitions transport method characterized in that it comprises a bomb. The method of claim 11, Said step of communicating guidance information from an automatic bomb control device to said munitions comprises communicating guidance information from a military GPS receiver to said munitions, wherein said munitions comprise a civilian GPS receiver, said information being said A munitions conveying method characterized by improving the accuracy of the munitions guidance system. The method of claim 11, And affixing the control device to the leg of the airplane crew. The method of claim 11, The step of communicating the induction information from the automatic control device of the munitions includes communicating an error signal from the control device to the munitions, wherein the error signal allows the accuracy of the munitions to be improved. Way. In the control device of GPS guided munitions transported by airplane, a) military GPS receiver, b) a radio transmitter for transmitting GPS information from the control device to the GPS guided munitions Including, The control device And to operate automatically to alleviate the need for retrofitting the plane. The method of claim 16, And a comparison circuit for comparing an output of the civil GPS receiver with an output of the civil GPS receiver and an output of the military GPS receiver to generate an error signal according to a difference between the outputs of the military GPS receiver and the civil GPS receiver. And a signal is provided to the radio transmitter for transmission of the GPS guided munitions to improve the accuracy of the GPS guided munitions. In judo munitions, a) GPS receiver, b) an actuator mechanism responsive to said GPS receiver, c) a plurality of pins controlled by the actuator mechanism, d) two antennas for the GPS receiver disposed on each of two different pins, e) switching circuit for alternately connecting said GPS receiver to each of said two antennas; Including, Guided munitions characterized in that the positional information generated through the use of the two antennas determines the rolling attitude of the munitions. In the method of improving the accuracy of munitions, a) alternately receiving GPS signals from each of two different antennas attached to two different pins of the munition; b) determining a location of the munition and a rolling attitude of the munition using the received GPS signal; c) guiding the munition to the target using the position of the munition, the rolling attitude of the munition, and the position of the target, wherein the rolling attitude of the munition causes the flight control surface to move to guide the munition to the target. Method for improving the accuracy of munitions, characterized in that.